23 research outputs found
New constraints on the 1.4 GHz source number counts and luminosity functions in the Lockman Hole field
We present a study of the 1173 sources brighter than Jy detected over an area of in the
Lockman Hole field. Exploiting the multi-band information available in this
field for 79% of the sample, sources have been classified into radio loud
(RL) active galactic nuclei (AGNs), star forming galaxies (SFGs) and radio
quiet (RQ) AGNs, using a variety of diagnostics available in the literature.
Exploiting the observed tight anti-correlations between IRAC band 1 or band 2
and the source redshift we could assign a redshift to 177 sources missing a
spectroscopic measurement or a reliable photometric estimate. A Monte Carlo
approach was used to take into account the spread around the mean relation. The
derived differential number counts and luminosity functions at several
redshifts of each population show a good consistency with models and with
earlier estimates made using data from different surveys and applying different
approaches. Our results confirm that below Jy SFGsRQ AGNs
overtake RL AGNs that dominate at brighter flux densities. We also confirm
earlier indications of a similar evolution of RQ AGNs and SFGs. Finally, we
discuss the angular correlation function of our sources and highlight its
sensitivity to the criteria used for the classification.Comment: 14 pages, 10 figures, 4 tables, MNRAS in pres
FR II radio galaxies at low frequencies – II. Spectral ageing and source dynamics
In this paper, the second in a series investigating FR II radio galaxies at low frequencies, we use LOFAR and VLA observations between 117 and 456 MHz in addition to archival data to determine the dynamics and energetics of two radio galaxies, 3C452 and 3C223, through fitting of spectral ageing models on small spatial scales. We provide improved measurements for the physical extent of the two sources, including a previously unknown low surface brightness extension to the northern lobe of 3C223, and revised energetics based on these values. We find spectral ages of and Myr for 3C452 and 3C223 respectively suggesting a characteristic advance speed for the lobes of around one per cent the speed of light. For 3C452 we show that, even for a magnetic field strength not assumed to be in equipartition, a disparity of factor of approximately 2 exists between the spectral age and that determined from a dynamical standpoint. We confirm that the injection index of both sources (as derived from the lobe emission) remains steeper than classically assumed values even when considered on well resolved scales at low frequencies, but find an unexpected sharp discontinuity between the spectrum of the hotspots and the surrounding lobe emission. We suggest that this discrepancy is due to the absorption of hotspot emission and/or non-homogeneous and additional acceleration mechanisms and, as such, hotspots should not be used in the determination of the underlying initial electron energy distribution
Improving total body irradiation with a dedicated couch and 3D-printed patient-specific lung blocks: A feasibility study
Introduction: Total body irradiation (TBI) is an important component of the conditioning regimen in patients undergoing hematopoietic stem cell transplants. TBI is used in very few patients and therefore it is generally delivered with standard linear accelerators (LINACs) and not with dedicated devices. Severe pulmonary toxicity is the most common adverse effect after TBI, and patient-specific lead blocks are used to reduce mean lung dose. In this context, online treatment setup is crucial to achieve precise positioning of the lung blocks. Therefore, in this study we aim to report our experience at generating 3D-printed patient-specific lung blocks and coupling a dedicated couch (with an integrated onboard image device) with a modern LINAC for TBI treatment. Material and methods: TBI was planned and delivered (2Gy/fraction given twice a day, over 3 days) to 15 patients. Online images, to be compared with planned digitally reconstructed radiographies, were acquired with the couch-dedicated Electronic Portal Imaging Device (EPID) panel and imported in the iView software using a homemade Graphical User Interface (GUI). In vivo dosimetry, using Metal-Oxide Field-Effect Transistors (MOSFETs), was used to assess the setup reproducibility in both supine and prone positions. Results: 3D printing of lung blocks was feasible for all planned patients using a stereolithography 3D printer with a build volume of 14.5×14.5×17.5 cm3. The number of required pre-TBI EPID-images generally decreases after the first fraction. In patient-specific quality assurance, the difference between measured and calculated dose was generally<2%. The MOSFET measurements reproducibility along each treatment and patient was 2.7%, in average. Conclusion: The TBI technique was successfully implemented, demonstrating that our approach is feasible, flexible, and cost-effective. The use of 3D-printed patient-specific lung blocks have the potential to personalize TBI treatment and to refine the shape of the blocks before delivery, making them extremely versatile
Care pathways models and clinical outcomes in disorders of consciousness
Objective: Patients with Disorders of consciousness, are persons with extremely low functioning levels and represent a challenge for health care systems due to their high needs of facilitating environmental factors. Despite a common Italian health care path-way for these patients, no studies have analyzed information on how each region have implemented it in its welfare system correlating data with patients’ clinical outcomes.
Materials and Methods: A multicenter observational pilot study was realized. Clinicians collected data on the care pathways of patients with Disorder of consciousness by ask-ing 90 patients’ caregivers to complete an ad hoc questionnaire through a structured phone interview. Questionnaire consisted of three sections: sociodemographic data, description of the care pathway done by the patient, and caregiver evaluation of health services and information received.Results: Seventy- three patients were analyzed. Length of hospital stay was different across the health care models and it was associated with improvement in clinical diag-nosis. In long- term care units, the diagnosis at admission and the number of caregivers available for each patient (median value=3) showed an indirect relationship with worsening probability in clinical outcome. Caregivers reported that communication with professionals (42%) and the answer to the need of information were the most critical points in the acute phase, whereas presence of Non- Governmental Organizations (25%) and availability of psychologists for caregivers (21%) were often missing during long-term care. The 65% of caregivers reported they did not know the UN Convention on the Rights of Persons with Disabilities.
Conclusion: This study highlights relevant differences in analyzed models, despite a recommended national pathway of care. Future public health considerations and ac-tions are needed to guarantee equity and standardization of the care process in all European countries
Laparoscopic bariatric surgery is safe during phase 2-3 of COVID-19 pandemic in Italy: A multicenter, prospective, observational study
Background: Sars-Cov-2 epidemic in Italy caused one of the greatest 2020 European outbreaks, with suspension of elective bariatric/metabolic surgery (BMS). From May 2020 a significant decline of the epidemic has been observed (phase 2); National Health Service protocols permitted elective BMS' resumption. A new, more severe COVID-19 surge, the "second wave", started on October 2020 (phase 3).Aim: The primary end point was to analyze the outcomes of any Sars-Cov-2 infection and related morbidity/mortality within 30 POD after laparoscopic BMS during phase 2-3; secondary end points were readmission and reoperation rates.Methods: Study design prospective, multicenter, observational.Setting: Eight Italian high-volume bariatric centers. All patients undergoing BMS from July 2020 through January 2021 were enrolled according to the following criteria: no Sars-Cov-2 infection; primary procedures; no concomitant procedure; age > 18 < 60 years; compensated comorbidities; informed consent including COVID-19 addendum; adherence to specific admission, in-hospital and follow-up protocols. Data were collected in a prospective database. Patients undergone BMS during July-December 2019 were considered a control group.Results: 1258 patients were enrolled and compared with 1451 operated on in 2019, with no differences for demographics, complications, readmission, and reintervention rates. Eight patients (0.6%) tested positive for Sars-Cov-2 infection after discharge, as well as and 15 healthcare professionals, with no related complications or mortality.Conclusions: Introduction of strict COVID-19 protocols concerning the protection of patients and health-care professionals guaranteed a safe resumption of elective BMS in Italy. The safety profile was, also, maintained during the second wave of outbreak, thus allowing access to a cure for the obese population. (C) 2021 Elsevier B.V. All rights reserved
The Australia Telescope 20 GHz (AT20G) Survey: The Bright Source Sample
The Australia Telescope 20 GHz (AT20G) Survey is a blind survey of the whole
Southern sky at 20 GHz (with follow-up observations at 4.8 and 8.6 GHz) carried
out with the Australia Telescope Compact Array (ATCA) from 2004 to 2007. The
Bright Source Sample (BSS) is a complete flux-limited subsample of the AT20G
Survey catalogue comprising 320 extragalactic (|b|>1.5 deg) radio sources south
of dec = -15 deg with S(20 GHz) > 0.50 Jy. Of these, 218 have near simultaneous
observations at 8 and 5 GHz. In this paper we present an analysis of radio
spectral properties in total intensity and polarisation, size, optical
identifications and redshift distribution of the BSS sources. The analysis of
the spectral behaviour shows spectral curvature in most sources with spectral
steepening that increases at higher frequencies (the median spectral index
\alpha, assuming S\propto \nu^\alpha, decreases from \alpha_{4.8}^{8.6}=0.11
between 4.8 and 8.6 GHz to \alpha_{8.6}^{20}=-0.16 between 8.6 and 20 GHz),
even if the sample is dominated by flat spectra sources (85 per cent of the
sample has \alpha_{8.6}^{20}>-0.5). The almost simultaneous spectra in total
intensity and polarisation allowed us a comparison of the polarised and total
intensity spectra: polarised fraction slightly increases with frequency, but
the shapes of the spectra have little correlation. Optical identifications
provided an estimation of redshift for 186 sources with a median value of 1.20
and 0.13 respectively for QSO and galaxies.Comment: 34 pages, 19 figures, tables of data included, replaced with version
published in MNRA
The 2020 Italian Society of Arterial Hypertension (SIIA) practical guidelines for the management of primary aldosteronism
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VizieR Online Data Catalog: H-ATLAS NGP LOFAR radio catalogue (Hardcastle+, 2016)
The NGP field was observed in four separate pointings, chosen to maximize sky covered, with the LOFAR HBA as part of the Surveys Key Science project. Observations used the HBADUALINNER mode, meaning that the station beams of core and remote stations roughly matched each other and giving the widest possible field of view. The first observation, which was made early on in LOFAR operations, was of slightly longer duration (~10h) than the others (~8h). International stations were included in some of the observations in 2014 but were not used in any of our analysis, which uses only the Dutch array. (1 data file)
VizieR Online Data Catalog: Bootes field LOFAR 150-MHz observations (Williams+, 2016)
Here, we report on the first LOFAR Cycle 2 High Band Antenna (HBA) observations of the Bootes field. The Bootes field is one of the Tier-3 Survey fields, and the aim is to eventually survey this field to the extreme rms depth of 12uJy/beam (1σ) at 150MHz. The Bootes field was observed on 2014 August 10 with the LOFAR HBA stations. (2 data files)
LOFAR and APERTIF Surveys of the Radio Sky : Probing Shocks and Magnetic Fields in Galaxy Clusters
At very low frequencies, the new pan-European radio telescope LOFAR is opening the last unexplored window of the electromagnetic spectrum for astrophysical studies. The revolutionary APERTIF-phased arrays that are about to be installed on the Westerbork radio telescope (WSRT) will dramatically increase the survey speed for the WSRT. Combined surveys with these two facilities will deeply chart the northern sky over almost two decades in radio frequency from similar to 15 up to 1400 MHz. Here we briefly describe some of the capabilities of these new facilities and what radio surveys are planned to study fun-damental issues related to the formation and evolution of galaxies and clusters of galaxies. In the second part we briefly review some recent observational results directly showing that diffuse radio emission in clusters traces shocks due to cluster mergers. As these diffuse radio sources are relatively bright at low frequencies, LOFAR should be able to detect thousands of such sources up to the epoch of cluster formation. This will allow addressing many question about the origin and evolution of shocks and magnetic fields in clusters. At the end we briefly review some of the first and very preliminary LOFAR results on clusters.Peer reviewe